My experience with Fleck 5600's is that the average life of one is around 7 years. My last one died in 7 years. The more TDS your water has, the quicker the cylinder will get scuffed up. I do not recommend a rebuild kit. I have gone in behind other softener people who have installed a rebuild kit only to have it doing the same thing in several months.

The other consideration is: how long has that unit been in service? Do you have city water or well water? If city water, you have chlorine. Chlorine degrades the mineral in the unit shortening it's life and cuts down on it's efficiency. If you replace the head, you may find that you will have to replace the mineral bed soon. Now you practically have a new softener.

The more TDS your water has, the quicker the cylinder will get scuffed up.
If city water, you have chlorine. Chlorine degrades the mineral in the unit shortening it's life and cuts down on it's efficiency.

Is there something the OP can put upstream so that both the softener and the gadget, working together, provide a very long life for the money paid?
". . .the interaction of multiple elements in a system to produce an effect different from or greater than the sum of their individual effects."
I guess I'm assuming the gadget's initial cost + maintenance cost is less than the softener's initial cost + maintenance cost.

Seems like investing in a water test may be worthwhile to figure out the root cause of failure since a few hundred are riding on this.
If the water test results are considered "perfect information" then thishttp://en.wikipedia.org/wiki/Expecte...ct_information
may apply.

If you wanted to protect your mineral from the effects of chlorine, you can put a carbon filter in front of it. This will remove the chlorine before the softener sees it. I don't recommend in line filters like the big box stores sell. The carbon filter would be roughly the same size as the softener.

Yes, the knob turns hard, but I'd rather spend $150 than $250. Is there any merit to replacing just the valve/piston/lower component and keep the old timer/top component? It doesn't seem like there's any problem with the electric part of the equation.